Light guide plate assembly, backlight module and display device

ABSTRACT

Provided are a light guide plate assembly, a backlight module, and a display device, which relate to the field of display technologies, and improve uniformity of the light intensity of light emitted from different areas in the light guide plate assembly. The light guide plate assembly includes a reflection portion having an aperture; and a transmission portion. At least part of the transmission portion is located in the aperture. The transmission portion includes a converging portion and a diverging portion. The converging portion is configured to make light that enters the converging portion be converged towards a direction away from a center of the aperture. The diverging portion is configured to make light that enters the diverging portion be diverged towards a direction away from the center of the aperture. The converging portion is located at a side of the transmission portion away from the center of the aperture.

CROSS-REFERENCE TO RELATED DISCLOSURE

The present disclosure claims priority to Chinese Patent Disclosure No.202211399410.9, filed on Nov. 9, 2022, the content of which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to the field of display technologies, andparticularly, to a light guide plate assembly, a backlight module and adisplay device.

BACKGROUND

With the development of display technologies, flat panel devices such asLCD (Liquid Crystal Display) panels are widely used in variouselectronic products such as cell phones, TVs, digital cameras, andnotebook computers due to the advantages of a high quality, powersaving, and a wide application range, and thus have become a mainstreamof display devices.

Since the liquid crystal display panel itself does not emit light, theLCD display panel needs to be used together with a backlight module.However, the backlight module in the related art has a problem of unevenbrightness.

SUMMARY

In an aspect, the present disclosure provides a light guide plateassembly. The light guide plate assembly includes a reflection portionhaving an aperture; and a transmission portion. At least part of thetransmission portion is located in the aperture. The transmissionportion includes a converging portion and a diverging portion; theconverging portion is configured to make light that enters theconverging portion be converged towards a direction away from a centerof the aperture. The diverging portion is configured to make light thatenters the diverging portion be diverged towards a direction away fromthe center of the aperture; and the converging portion is located at aside of the transmission portion away from the center of the aperture.

In another aspect, the present disclosure provides a backlight module.The backlight module includes a light-emitting element and the lightguide plate assembly described above. The light guide plate assembly islocated at a light-exiting side of the light-emitting element.

In another aspect, the present disclosure provides a display device. Thedisplay device includes a display panel and the backlight moduledescribed above. The display panel is located at a light-exiting side ofthe backlight module.

BRIEF DESCRIPTION OF DRAWINGS

In order to more clearly illustrate technical solutions of embodimentsof the present disclosure, the accompanying drawings used in theembodiments are described below. The drawings described below are merelya part of the embodiments of the present disclosure. Based on thesedrawings, those skilled in the art can obtain other drawings.

FIG. 1 is a perspective diagram of a light guide plate assemblyaccording to an embodiment of the present disclosure;

FIG. 2 shows a sectional view along AA′ in FIG. 1 according to anembodiment of the present disclosure;

FIG. 3 is a sectional view of a backlight module according to anembodiment of the present disclosure;

FIG. 4 is an enlarged schematic diagram of a light guide plate unitaccording to an embodiment of the present disclosure;

FIG. 5 is a sectional view of a light guide plate unit according toanother embodiment of the present disclosure;

FIG. 6 is a sectional view of a light guide plate unit according toanother embodiment of the present disclosure;

FIG. 7 is a sectional view of a light guide plate unit according toanother embodiment of the present disclosure;

FIG. 8 is a sectional view of a light guide plate unit according toanother embodiment of the present disclosure;

FIG. 9 is a sectional view of a light guide plate unit according toanother embodiment of the present disclosure;

FIG. 10 is a sectional view of a light guide plate unit according toanother embodiment of the present disclosure;

FIG. 11 is a sectional view of a light guide plate unit according toanother embodiment of the present disclosure;

FIG. 12 is a layer diagram of a backlight module according to anembodiment of the present disclosure;

FIG. 13 is a sectional view of a light guide plate unit according toanother embodiment of the present disclosure;

FIG. 14 is a schematic diagram of a position disposing principle of athird microstructure of a light guide plate unit according to anembodiment of the present disclosure;

FIG. 15 is a sectional view of a light guide plate unit according toanother embodiment of the present disclosure; and

FIG. 16 is a schematic diagram of a display device according to anembodiment of the present disclosure.

DESCRIPTION OF EMBODIMENTS

In order to better illustrate technical solutions of the presentdisclosure, the embodiments of the present disclosure are described indetails with reference to the drawings.

It should be noted that the described embodiments are merely part of theembodiments of the present disclosure rather than all of theembodiments. All other embodiments obtained by those skilled in the artshall fall into the protection scope of the present disclosure.

The terms used in the embodiments of the present disclosure are merelyfor the purpose of describing specific embodiment, rather than limitingthe present disclosure. The terms “a”, “an”, “the” and “said” in asingular form in the embodiments of the present disclosure and theattached claims are also intended to include plural forms thereof,unless noted otherwise.

It should be understood that the term “and/or” used in the context ofthe present disclosure is to describe a correlation relation of relatedobjects, indicating that there can be three relations, e.g., A and/or Bcan indicate only A, both A and B, and only B. In addition, the symbol“/” in the context generally indicates that the relation between theobjects in front and at the back of “/” is an “or” relationship.

The embodiments of the present disclosure provide a light guide plateassembly. FIG. 1 is a perspective diagram of a light guide plateassembly 1 according to an embodiment of the present disclosure. Asshown in FIG. 1 , the light guide plate assembly 1 has a light-incomingside 101 and a light-exiting side 102 that are opposite to each otheralong a thickness direction h1 of the light guide plate assembly 1. Thelight guide plate assembly 1 can transmit light emitted from alight-emitting element, so that the light emitted from thelight-emitting element comes to the light-incoming side 101 of the lightguide plate assembly 1, and exits from the light-exiting side 102 of thelight guide plate assembly 1. In FIG. 1 , arrows passing through thelight guide plate assembly 1 are used to indicate a propagationdirection of the light passing through the light guide plate assembly 1.When the light guide plate assembly 1 and the light-emitting elementtogether form a backlight module, the light-emitting element can bedisposed at a side adjacent to the light-incoming side 101 side of thelight guide plate assembly 1.

FIG. 2 shows a sectional view along AA′ in FIG. 1 according to anembodiment of the present disclosure. In combination with FIG. 1 andFIG. 2 , the light guide plate assembly 1 includes light guide plateunits 10 that are arranged in an array in a direction parallel to aplane of the light guide plate assembly 1. As shown in FIG. 1 , a firstdirection h21 and a second direction h22 intersect to define the planeof the light guide plate assembly 1.

As shown in FIG. 1 and FIG. 2 , the light guide plate unit 10 has alight-emitting element disposing area A1. The light-emitting elementdisposing area A1 is configured to dispose the light-emitting element.Exemplarily, when the light guide plate assembly 1 and a backlightsource together form a backlight module, according to some embodimentsof the present disclosure, the light-emitting elements in the backlightsource and the light guide plate units can be arranged in a one-to-onecorrespondence. In combination with FIG. 3 , which is a sectional viewof a backlight module 100 according to an embodiment of the presentdisclosure, the light-emitting element 30 is located in thelight-emitting element disposing area A1.

As shown in FIG. 2 and FIG. 3 , the light guide plate unit 10 furtherincludes a reflection portion 11 and a transmission portion 12. Thereflection portion 11 is configured to reflect light emitted from thelight-emitting element (not shown in FIG. 2 ). The transmission portion12 is configured to transmit light emitted from the light-emittingelement (not shown in FIG. 2 ). The reflectivity of the reflectionportion 11 is greater than the reflectivity of the transmission portion12. The transmittance of the transmission portion 12 is greater than thetransmittance of the reflection portion 11.

In some embodiments of the present disclosure, as shown in FIG. 2 andFIG. 3 , the reflection portion 11 has an aperture H. At least part ofthe transmission portion 12 is located in the aperture H. Theabove-mentioned light-emitting element disposing area A1 is located inthe aperture H. As shown in FIG. 3 , when the light guide plate assembly1 is used in the backlight module 100, the light-emitting element 30 inthe backlight module 100 can be disposed in the aperture H.

As shown in FIG. 2 and FIG. 3 , the transmission portion 12 includes adiverging portion 121 and a converging portion 122. The divergingportion 121 is configured to make light that enters the divergingportion 121 diverge towards a direction away from the center of theaperture H. The converging portion 122 is configured to make light thatenters the converging portion 122 converge towards a direction away fromthe center of the aperture H. Exemplarily, the converging portion 122can make light that enters the converging portion 122 converge towardsan edge S of the aperture H. The edge S of the aperture H refers to anedge located at a side of the aperture H adjacent to the light-exitingside 102 of the light guide plate assembly 1.

FIG. 4 is an enlarged schematic diagram of a light guide plate unitaccording to an embodiment of the present disclosure. When lighting thebacklight module 100, referring to FIG. 3 and FIG. 4 , light emittedfrom the light-emitting element 30 is refracted when passing through theconverging portion 122, so that the exiting light can deflect towards adirection adjacent to the edge S of the aperture H relative to theincoming light. That is, multiple beams of light passing through theconverging portion 122 can converge towards a position adjacent to theedge S of the aperture H. Light emitted from the light-emitting element30 is refracted when passing through the diverging portion 121, and theexiting light can deflect towards a direction adjacent to the edge S ofthe aperture H relative to the incoming light. That is, multiple beamsof light passing through the diverging portion 121 can diverge towards adirection away from the center of the aperture H.

According to the embodiments of the present disclosure, the light guideplate assembly 1 includes the transmission portion 12 and the reflectionportion 11, and the reflection portion 11 has an aperture H in which atleast part of the transmission portion 12 is located. In this case, whenthe light guide plate assembly 1 is applied to a backlight module, thelight-emitting element can also be disposed in the aperture H. With sucha configuration, small-angle light emitted from the light-emittingelement can exit after passing through the transmission portion 12located in the corresponding aperture H, large-angle light emitted fromthe light-emitting element is reflected by the reflection portion 11 andthe reflected light exits after passing through the transmission portioncorresponding to the reflection surface, so that the large-angle lightcan be prevented from being directed to a position of the otherlight-emitting element, thereby avoiding the mutual crosstalk of lightemitted from different light-emitting elements. Moreover, with such aconfiguration, the light intensity of light emitted from an area where anon-aperture position of the reflection portion in the light guide plateassembly is located can be improved, which is conducive to improving theuniformity of the light intensity of light emitted from different areasin the light guide plate assembly.

In addition, in the embodiments of the present disclosure, thetransmission portion 12 includes the diverging portion 121 and theconverging portion 122. The diverging portion 121 can make light thatenters the diverging portion 121 be diverged towards a direction awayfrom the center of the aperture H, and the converging portion 122 canmake light that enters the converging portion 122 be converged towards adirection away from the center of the aperture H. Based on such aconfiguration, when the light guide plate assembly 1 is applied to thebacklight module, the light intensity of light emitted from an areaadjacent to the edge S of the aperture of the reflection portion in thelight guide plate assembly 1 can be further improved to balance thelight intensity of light emitted from different positions such as anarea (such as the center of the aperture) provided with thelight-emitting element and an area (such as the edge of the aperture)not provided with the light-emitting element in the aperture H, so thatit can eliminate a visible mesh pattern caused by uneven lightintensity, thereby improving the display effect of the display deviceincluding the light guide plate assembly 1.

Moreover, based on the configuration manner provided by the embodimentsof the present disclosure, a visible mesh pattern can be avoided withoutneeding to provide a diffusion plate in the light guide plate assembly,thereby being conducive to saving the cost of the light guide plateassembly 1 and reducing the thickness of the light guide plate assembly1.

When the diverging portion 121 and the converging portion 122 aredisposed, exemplarily, as shown in FIG. 2 , FIG. 3 , and FIG. 4 , thediverging portion 121 in the light guide plate unit 10 is disposed tocorrespond to the above-mentioned light-emitting element disposing areaA1. That is, an orthographic projection of the diverging portion 121 onthe plane of the light guide plate assembly 1 is located in thelight-emitting element disposing area A1. The converging portion 122 isdisposed to avoid the light-emitting element disposing area A1. That is,the orthographic projection of the converging portion 122 on the planeof the light guide plate assembly is disposed to avoid thelight-emitting element disposing area A1.

Exemplarily, as shown in FIG. 2 , FIG. 3 , and FIG. 4 , in someembodiments of the present disclosure, the converging portion 122 can bedisposed adjacent to the edge S of the aperture H. When the light guideplate assembly 1 and the light-emitting element 30 together form abacklight module 100, and when the light-emitting element 30 is disposedcorresponding to the center of the aperture H, the converging portion122 and the light-emitting element 30 can be misaligned with each otherin a thickness direction h1 of the light guide plate assembly 1, asshown in FIG. 3 , and FIG. 4 . Such a configuration can make morelarge-angle light be directed to the converging portion 122. In someembodiments of the present disclosure, a light-exiting angle refers toan acute angle formed between a propagation direction of light emittedfrom the light-emitting element 30 and the thickness direction of thelight guide plate assembly 1. The large-angle light refers to lightemitted from the light-emitting element 30 that has a large anglebetween the light and the thickness direction h1 of the light guideplate assembly 1. Taking the large-angle light R11, R12, and R13 shownin FIG. 4 as an example, in a process during which these light passesthrough the light guide plate assembly 1, these light can be convergedtowards the edge S of the aperture H due to the converging portion 122.Based on the configuration manner provided by the embodiments of thepresent disclosure, the large-angle light can be used to increase thelight intensity at the position of the edge S of the aperture H, theutilization rate of the large-angle light can be increased, and thelarge-angle light can be prevented from further being directed to anarea where other light-emitting components 30 are located, that is,avoiding the mutual crosstalk of the light emitted from differentlight-emitting elements 30.

Exemplarily, as shown in FIG. 2 , FIG. 3 , and FIG. 4 , in someembodiments of the present disclosure, the diverging portion 121 isdisposed corresponding to the center of the aperture H. When the lightguide plate assembly 1 and the light-emitting element 30 together form abacklight module 100, as mentioned above, in the embodiments of thepresent disclosure, the light-emitting element 30 is disposedcorresponding to the center of the aperture H, and the diverging portion121 is disposed corresponding to the center of the aperture H, so thatsmall-angle light can be directed to the diverging portion 121 as muchas possible. Herein, the small-angle light refers to light having asmall angle emitted from the light-emitting element 30 that has a smallangle formed between the light and the thickness direction h1 of thelight guide plate assembly 1. Taking the small-angle light R21 and R22shown in FIG. 4 as an example, in a process during which the lightpasses through the light guide plate assembly 1, the light can bediverged towards a direction away from the center of the aperture H dueto the diverging portion 121. Compared with the large-angle light, thesmall-angle light emitted from the light-emitting element 30 has largerlight intensity. In some embodiments of the present disclosure, thediverging portion 121 diverges the small-angle light emitted from thelight-emitting element 30, so that the amount of small-angle lightemitted to the center of the aperture H is reduced, and the lightintensity at the center of the aperture H is reduced. In this way, thelight intensity at the center of the aperture H tend to be consistentwith the light intensity at the edge of the aperture H.

In some embodiments, as shown in FIG. 2 , FIG. 3 , and FIG. 4 , thereflection portion 11 includes a reflection surface 111 and a bottomsurface 112 located at a side adjacent to a light-incoming side of thelight guide plate assembly 1. An angle α1 is formed between thereflection surface 111 and the bottom surface 112, where 0°<α1<90°. Asshown in FIG. 4 , for some large-angle light (e.g., light R14) emittedfrom the light-emitting element 30, the reflection surface 111 canadjust the propagation direction of these light by reflection to avoidthe mutual crosstalk between these large-angle light and other lightemitted from the light-emitting element 30 at other positions.Exemplarily, as shown in FIG. 4 , after the light R14 is reflected bythe reflection surface 111, the reflected light can be directed to theconverging portion 122, and can be deflected towards the edge S of theaperture H after the action of the converging portion 122, therebyfurther increasing the brightness at the position adjacent to the edge Sof the aperture H.

Exemplarily, as shown in FIG. 2 , FIG. 3 , and FIG. 4 , the reflectionsurface 111 surrounds the aperture H. That is, the reflection portion 11forms a reflection cup structure with a cup-like shape.

Exemplarily, as shown in FIG. 2 , FIG. 3 , and FIG. 4 , the reflectionsurface 111 surrounds the converging portion 122, and the convergingportion 122 surrounds the diverging portion 121.

Exemplarily, as shown in FIG. 4 , the reflection surface 111 includes afirst portion 1111 and a second portion 1112. The second portion 1112 islocated at a side of the first portion 1111 adjacent to thelight-exiting side 102 of the light guide plate assembly 1. The firstportion 1111 is not in contact with the converging portion 122, and thesecond portion 1112 is in contact with the converging portion 122. Withsuch a configuration, the second portion 1112 firstly reflects part oflarge-angle light emitted from the light-emitting element 30, after thepropagation direction of this part of large-angle light is adjusted dueto the refection, the converging portion 122 can continue to act on thispart of light to make this part of light be converged towards the edge Sof the aperture H, thereby further increasing the light intensity at theposition adjacent to the edge of the aperture H.

Exemplarily, as shown in FIG. 2 , FIG. 3 , and FIG. 4 , in a directionperpendicular to the plane of light guide plate assembly 1, thediverging portion 121 does not overlap with the reflection surface 111,to avoid the reflection of small-angle light by the reflection surface111, thereby reducing the loss of small-angle light caused byreflection.

Exemplarily, as shown in FIG. 2 , FIG. 3 , and FIG. 4 , in someembodiments of the present disclosure, a surface of the convergingportion 122 adjacent to the light-incoming side of the light guide plateassembly 1 can have a curvature greater than 0. That is, as shown inFIG. 4 , the converging portion 122 includes a convex lens 1220 adjacentto a side of the light-emitting element 30, and the convex lens 1220 islocated at a side of the transmission portion 12 adjacent to thelight-incoming side 101 of the light guide plate assembly 1.

Exemplarily, as shown in FIG. 4 , the reflection surface 111 includes afirst edge S1 adjacent to the light-exiting side 102 of the light guideplate assembly 1 and a second edge S2 adjacent to the light-incomingside 101 of the light guide plate assembly 1. The first edge S1 is theedge S of the aperture H adjacent to the light-exiting side 102 of thelight guide plate assembly 1. In a direction parallel to the plane ofthe light guide plate assembly 1, the second edge S2 is located at aside of the first edge S1 adjacent to the center of the aperture H.

When arranging the convex lens 1220, in some embodiments of the presentdisclosure, the focus O₁ of the convex lens 1220 can be disposed on thefirst edge S1, that is, the focus O₁ overlaps with the first edge S1.With such a configuration, the light directed to the convex lens 1220can be converged at the position of the edge S of the aperture afterpassing through the convex lens 1220, thereby increasing the brightnessat the position of the edge S of the aperture H.

It should be noted that in the light guide plate assembly 1, the firstedge S1 can be a closed ring that surrounds the aperture H. In thesection view of the light guide plate assembly 1 indicated by FIG. 4 ,the position of the first edge S1 is schematically shown by an upperendpoint of the reflection surface 111 adjacent to the aperture H.

Alternatively, in some embodiments of the present disclosure, the focusO₁ of the convex lens 1220 can be disposed to avoid the non-apertureposition of the reflection portion 11. In some embodiments of thepresent disclosure, as shown in FIG. 4 , the focus O₁ of the convex lens1220 can be disposed at a side of the reflective surface 111 adjacent tothe light-exiting side 102 of the light guide plate assembly 1. FIG. 4schematically shows that the focus O₁ of the convex lens 1220 isdisposed directly above the first edge S1. In FIG. 4 , the focus O₁ ofthe convex lens 1220 is located at a side of the reflection portion 11adjacent to the light-exiting side 102 of the light guide plate assembly1, and an orthographic projection of the focus O₁ of the convex lens1220 onto the plane of the light guide plate assembly 1 is disposed onthe first edge S1.

In the embodiments of the present disclosure, the focus O₁ of the convexlens 1220 is disposed to avoid the non-aperture position of thereflection portion 11, or the focus O₁ of the convex lens 1220 isdisposed on the first edge S1, so that the light directed to the convexlens 1220 can be prevented from converging into the reflection portion11. Due to the loss of light when the light is reflected, such aconfiguration can reduce the loss of the converged light when exitingfrom the light guide plate assembly 1, thereby increasing the lightintensity utilization rate of the backlight module 100 including thelight guide plate assembly 1. Moreover, With such a configuration, onthe basis of increasing the light intensity at the position adjacent tothe edge S of the aperture H, the small-angle light emitted from thelight-emitting element 30 can be directed to the reflection surface 111as little as possible after passing through the transmission portion 12,thereby reducing the loss of the small-angle light caused by reflection.

When arranging the diverging portion 121, in some embodiments of thepresent disclosure, as shown in FIG. 2 , FIG. 3 , and FIG. 4 , thecurvature of the surface of the diverging portion 121 adjacent to thelight-incoming side 101 of the light guide plate assembly 1 can besmaller than 0. That is, as shown in FIG. 4 , the diverging portion 121includes a concave lens 1210, and the concave lens 1210 is located at aside of the transmission portion 12 adjacent to the light-incoming side101 of the light guide plate assembly 1.

FIG. 5 is a sectional view of a light guide plate unit according toanother embodiment of the present disclosure. In some embodiments of thepresent disclosure, as shown in FIG. 5 , a surface of the convergingportion 122 adjacent to a light-incoming side 101 of the light guideplate assembly 1 includes a first surface P1. A curvature of the firstsurface P1 can be set to 0, and along a direction X1 from the edge ofthe aperture H to a center of the aperture H, a distance between thefirst surface P1 and a light-exiting surface of the light guide plateassembly 1 gradually decreases. The light-exiting surface of the lightguide plate assembly 1 is a surface of the light guide plate assembly 1adjacent to the light-exiting side 102. That is, the first surface P1 isinclined relative to the plane of the light guide plate assembly 1, sothat an angle is formed between the first surface P1 and the plane ofthe light guide plate assembly 1. As shown in FIG. 5 , a shape of thefirst surface P1 in a cross-sectional view is a straight line.

For part of the large-angle light emitted from the light-emittingelement 30 towards the first surface P1, taking the light R15 shown inFIG. 5 as an example, compared with the incoming light, the refractedlight obtained after the light R15 passes through the first surface P1is deflected towards a direction closer to the edge S of the aperture H,thereby increasing the light intensity at the position of the edge S ofthe aperture H.

For part of the small-angle light emitted from the light-emittingelement 30 towards the first surface P1, taking the light R23 shown inFIG. 5 as an example, after passing through the first surface P1, therefracted light corresponding to the light R23 can avoid the reflectionsurface 111 to exit after passing through the transmission portion 12.Such a configuration can reduce the loss of small-angle light caused byreflection.

Exemplarily, the first surface P1 can be a side surface of a circularplatform structure or a prism structure.

In some embodiments of the present disclosure, referring to FIG. 5 , asurface of the diverging portion 121 adjacent to a light-incoming side101 of the light guide plate assembly 1 includes a second surface P2. Acurvature of the first surface P2 can be set to 0. Along a direction X1from the edge of the aperture H to a center of the aperture H, adistance between the second surface P2 and a light-exiting surface ofthe light guide plate assembly 1 gradually decreases. For light emittedfrom the light-emitting element 30 towards the transmission portion 12,taking the light R23 shown in FIG. 5 as an example, compared with theincoming light, the refracted light obtained after the light R23 passesthrough the second surface P2 is deflected towards a direction away fromthe center of the aperture H, so that the light intensity at the centerof the aperture H can be reduced. Therefore, the light intensity at thecenter of the aperture H tends to be consistent with the light intensityat the edge of the aperture H.

Exemplarily, in some embodiments of the present disclosure, the secondsurface P2 and the first surface P1 can be a side surface of a samecircular platform structure or a same prism structure. That is, there isno inflection point between the first surface P1 and the second surfaceP2, so as to facilitate the processing of the diverging portion 121 andthe converging portion 122.

FIG. 6 is a sectional view of a light guide plate unit according toanother embodiment of the present disclosure. Exemplarily, as shown inFIG. 6 , the diverging portion 121 includes a third surface P3 adjacentto the light-incoming side 101 of the light guide plate assembly 1.Along the direction X1 from the edge S of the aperture H towards thecenter of the aperture H, a distance between the third surface P3 andthe light-exiting surface of the light guide plate assembly 1 decreasesand then increases, that is, the third surface P3 includes an undulationstructure 4 as shown in FIG. 6 . With such a configuration, whileimproving the consistency between the light intensity at the center ofthe aperture H and the light intensity at the edge S of the aperture H,a distance between the center of the diverging portion 121 and thelight-exiting surface of the light guide plate assembly 1 can beincreased, thereby avoiding an optical bright spot at the center of thediverging portion 121. Therefore, an image quality of the display moduleincluding the light guide plate assembly 1 can be improved.

It should be noted that between the edge and the center of the divergingportion 121, an undulation structure 4 provided at the third surface P3is only an illustration in FIG. 6 . Under a premise of satisfying adistance between the center of the diverging portion 121 and thelight-exiting surface of the light guide plate assembly 1, two or moreundulation structures 4 can be provided at the third surface P3 betweenthe edge and the center of the diverging portion 121, and the number ofthe undulation structures is not limited in the present disclosure.

Exemplarily, as shown in FIG. 6 , the third surface P3 includes a firstsub-surface P31 adjacent to the first surface P1, and the firstsub-surface P31 has a same curvature as the first surface P1. Forexample, the curvature of the first sub-surface P31 and the curvature ofthe first surface P1 can be 0, respectively. With such a configuration,a same processing process can be used to form the first surface P1 andthe first sub-surface P31.

In some embodiments of the present disclosure, as shown in FIG. 6 , thethird surface P3 further includes a second sub-surface P32 adjacent tothe center of aperture H, and the second sub-surface P32 has a V-shapedsection.

It should be noted that the structures shown in FIG. 4 , FIG. 5 , andFIG. 6 are merely an illustration. FIG. 7 is a sectional view of a lightguide plate unit according to another embodiment of the presentdisclosure. As shown in FIG. 7 , the converging portion 122 can includea convex lens 1220, and the curvature of the second surface P2 of thediverging portion 121 can be set to 0. FIG. 7 schematically shows thatthe diverging portion 121 has an inverted V-shape. Alternatively, thediverging portion 121 can have an M-like shape, which is not shown inthe drawings.

FIG. 8 is a sectional view of a light guide plate unit according toanother embodiment of the present disclosure. In some embodiments of thepresent disclosure, as shown in FIG. 8 , the curvature of the firstsurface P1 of the converging portion 122 can be set to 0, and thediverging portion 121 includes a concave lens 1210.

FIG. 9 is a sectional view of a light guide plate unit according toanother embodiment of the present disclosure. In some embodiments of thepresent disclosure, as shown in FIG. 9 , a surface of the convergingportion 122 adjacent to the light-incoming side 101 of the light guideplate assembly 1 includes a first microstructure 21. The firstmicrostructure 21 can make the propagation direction of part oflarge-angle light (e.g., large-angle light R16 shown in FIG. 9 ) emittedfrom the light-emitting element 30 to be adjusted for multiple times inthe converging portion 122. In the embodiments of the presentdisclosure, by treating the surface of the converging portion 122, thefirst microstructure 21 is provided at the surface of the convergingportion 122 adjacent to the light-incoming side 101 of the light guideplate assembly 1. In this way, more large-angle light can converge tothe position adjacent to the edge of the aperture H, thereby furtherincreasing the brightness at the edge of the aperture H, so that thelight intensity at the edge of the aperture H further tends to beconsistent with the light intensity at the center of the aperture H.Moreover, the first microstructure 21 can also scatter the light thatreaches the surface of the first microstructure 21, so that theuniformity of the light emitted from different positions of theconverging portion 122 can be further improved.

Exemplarily, as shown in FIG. 9 , the first microstructure 21 includes aprotruding structure. The protruding structure protrudes from theconverging portion 122 towards the light-incoming side 101 of the lightguide plate assembly 1. The protruding structure is equivalent to aconvex lens. The protruding structure can make multiple beams of lightthat reaches the surface of the protruding structure be converged in theprotruding structure, and this converging effect can overlay theconverging effect of the converging portion 122 to further increase thelight intensity of the light directed to the edge of the aperture H.

In some embodiments of the present disclosure, the protruding structurecan have a cone shape and/or a semi-oval sphere shape. FIG. 9schematically shows a cross-sectional view in which the protrudingstructure has a semi-oval sphere shape.

Exemplarily, as shown in FIG. 9 , a surface of the diverging portion 121adjacent to the light-incoming side 101 of the light guide plateassembly 1 includes a second microstructure 22. The secondmicrostructure 22 can make the propagation direction of part ofsmall-angle light (e.g., small-angle light R24 shown in FIG. 9 ) emittedfrom the light-emitting element 30 be adjusted multiple times in thediverging portion 121. With such a configuration, more small-angle lightcan be directed towards a direction away from the center of the apertureH, so that the light intensity at the center of the aperture H isfurther consistent with the light intensity at the edge of the apertureH. Moreover, the second microstructure 22 can also scatter the lightthat reaches the surface of the second microstructure 22, so that theuniformity of the light emitted from different positions of thediverging portion 121 can be further improved.

In some embodiments of the present disclosure, as shown in FIG. 9 , thesecond microstructure 22 includes a concave structure. The concavestructure is recessed towards the light-exiting side 102 of the lightguide plate assembly 1. The concave structure is equivalent to a concavelens. The concave structure can diverge multiple beams of light thatreaches the surface of the concave structure, and this diverging effectcan overlay the diverging effect of the diverging portion 121, so thatthe light intensity of the light directed to the center of the apertureH can be further reduced.

Exemplarily, the concave structure can have a cone and/or a semi-ovalsphere shape. FIG. 9 schematically shows a cross-sectional view in whichthe concave structure has a semi-oval sphere shape.

FIG. 10 is a sectional view of a light guide plate unit according toanother embodiment of the present disclosure, and FIG. 11 is a sectionalview of a light guide plate unit according to another embodiment of thepresent disclosure. Exemplarily, as shown in FIG. 10 and FIG. 11 , asurface of the transmission portion 12 adjacent to the light-exitingside 102 of the light guide plate assembly 1 includes a thirdmicrostructure 23. Along a direction parallel to the plane of the lightguide plate assembly 1, a distance L between the third microstructure 23and the center of the aperture H is greater than 0. When light reachesthe surface of the transmission portion 12 adjacent to the light-exitingside 102 of the light guide plate assembly 1, compared with configuringthis surface to be a flat surface, the third microstructure 23 canreduce the incident angle of the incoming light, that is, an angleformed between the incoming light and a normal line of the surface ofthe transmission portion 12 adjacent to the light-exiting side 102 ofthe light guide plate assembly 1 is reduced, so that the incident angleof the incoming light is smaller than a critical angle that would causetotal reflection. In this way, the incoming light can exit from thelight guide plate assembly normally, and the utilization rate of lightemitted from the light-emitting element 30 can be improved, therebyavoiding total reflection during the process of exiting from the lightguide plate assembly 1 and reducing the light loss.

Exemplarily, the third microstructure 23 includes a cone and/or asemi-oval sphere shape. FIG. 10 and FIG. 11 show a cross-sectional viewin which the third microstructure 23 has a cone shape.

Exemplarily, in some embodiments of the present disclosure, any one ofthe first microstructure 21, the second microstructure 22, and the thirdmicrostructure 23 can be processed by means of mechanical processingand/or etching. For example, in some embodiments of the presentdisclosure, any one of the first microstructure 21, the secondmicrostructure 22, and the third microstructure 23 that have a shape ofa cone and/or a semi-oval sphere shape can be formed at the surface ofthe light guide plate assembly 1 by a shaping mold. In some embodimentsof the present disclosure, when forming the second microstructure 22having the concave structure, convex points can be formed by etching atthe surface of the mold by means of an etching process, after that, whenforming the transmission portion 12 by means of an injection moldingprocess, the concave structure can be formed at the surface of thediverging portion 121.

Exemplarily, in some embodiments of the present disclosure, thereflection portion 11 and the transmission portion 12 can be formedseparately, and then bonded together by means of a colloid to improvethe bonding firmness.

Alternatively, in some embodiments of the present disclosure, thereflection portion 11 and the transmission portion 12 can be formed intoone piece, to simplify the molding process of the light guide plateassembly 1, and to improve the bonding firmness between the reflectionportion 11 and the transmission portion 12. Moreover, with such aconfiguration, there is no need to provide a glue frame for fixing therefection portion 11 and the transmission portion 12. When the lightguide plate assembly 1 is used for a backlight module, the border of thebacklight module can be narrower. For example, the reflection portion 11and the transmission portion 12 can be formed into one piece by aninjection molding process.

Exemplarily, the above reflection portion 11 includes a white materialto increase the reflectivity of the reflection portion 11. Exemplarily,the reflection portion 11 includes acrylic or polycarbonate (PC).

Exemplarily, the transmission portion 12 includes a transparentmaterial, to make the transmission portion 12 have a high transmissionrate for ensuring the transmission effect of the light.

The present disclosure further provides a backlight module. FIG. 12 is alayer diagram of a backlight module 100 according to an embodiment ofthe present disclosure. Referring to FIG. 3 , FIG. 4 , and FIG. 12 , thebacklight module 100 includes a light-emitting element 30 and the lightguide plate assembly 1. The light guide plate assembly 1 is located atthe light-exiting side of the light-emitting element 30.

When the backlight module 100 works, the light-emitting element 30 emitslight. The light emitted from the light-emitting element 30 is directedto the display panel located at the light-exiting side of the lightguide plate assembly 1 after the light guide effect of the light guideplate assembly 1, so as to display images by the display device.

In the backlight module 100 provided by the embodiments of the presentdisclosure, the light guide plate assembly 1 includes the transmissionportion 12 and the reflection portion 11, and the transmission portion12 includes the diverging portion 121 and the converging portion 122.When applied to the backlight module, the light intensity of the lightemitted from an area adjacent to the edge S of the aperture of thereflection portion 11 in the light guide plate assembly 1 can beincreased, thereby balancing the light intensity of light emitted fromdifferent positions such as an area provided with the light-emittingelement 30 and an area not provided with the light-emitting element 30,so that a visible mesh pattern caused by uneven light intensity can beavoided.

Moreover, based on the configuration provided by the embodiments of thepresent disclosure, a visible mesh pattern can be avoided withoutneeding to arrange a diffusion plate in the light guide plate assembly1, thereby saving the cost of the backlight module 100 and reducing thethickness of the backlight module 100.

Exemplarily, as shown in FIG. 3 and FIG. 12 , the backlight module 100includes multiple light-emitting elements 30. Multiple light-emittingelements 30 are arranged in an array in a plane of the backlight module100. Exemplarily, the light-emitting element 30 includes a Mini LEDchip.

Exemplarily, as shown in FIG. 3 and FIG. 12 , in the backlight module100, the reflection surface 111 of the light guide plate assembly 1surrounds the light-emitting element 30. With such a configuration, thereflection surface 111 can reflect more large-angle light emitted fromthe light-emitting element 30, so that the utilization rate of the lightemitted from the light-emitting element 30 can be increased, therebyreducing the mutual crosstalk of the light emitted from differentlight-emitting elements 30.

It is only a schematically example that FIG. 12 shows that a shape ofthe orthographic projection of the light-emitting element 30 onto theplane of the backlight module 100 is a quadrangle and a shape of theorthographic projection of the aperture H of the reflection portion 11onto the plane of the backlight module 100 is a circle, and the shape ofthe orthographic projection of the light-emitting element 30 and theshape of the orthographic projection of the aperture H onto the plane ofthe backlight module 100 can be configured according to different designrequirements in the embodiments of the present disclosure.

Exemplarily, as shown in FIG. 4 , along a direction parallel to theplane of the light guide plate assembly 1, the reflection portion 11 andlight-emitting elements 30 at least partially overlap with each other,that is, at least part of the light-emitting element 30 can be embeddedin the light guide plate assembly 1. Such a configuration is conductiveto a thinning design of the backlight module 100.

Exemplarily, as shown in FIG. 4 , the light-emitting element 30 islocated at a side of the transmission portion 12 adjacent to thelight-incoming side 101 of the light guide plate assembly 1, and atleast part of the light-emitting element 30 is located in the aperture Hto reduce the thickness of the backlight module 100.

Exemplarily, as shown in FIG. 4 , the light-emitting element 30 islocated at a side of the diverging portion 121 adjacent to thelight-incoming side 101 of the light guide plate assembly 1.

Exemplarily, as shown in FIG. 4 , along a thickness direction of thebacklight module 100, the light-emitting element 30 and the divergingportion 121 at least partially overlap with each other. Such aconfiguration can diverge the small-angle light emitted from thelight-emitting element 30 by using the diverging portion 121, so as tobalance brightness difference between a position where the backlightmodule 100 is provided with the light-emitting element 30 and a positionwhere the backlight module 100 is not provided with the light-emittingelement 30.

Exemplarily, as shown in FIG. 4 , along the thickness direction of thebacklight module 100, the light-emitting element 30 does not overlapwith the converging portion 122, to avoid that the small-angle lightemitted from the light-emitting element 30 is further converged by theconverging portion 122.

Exemplarily, as shown in FIG. 4 and FIG. 5 , the converging portion 122includes a first end D₁ adjacent to the diverging portion 121. An angleformed between a connection line D₁O₂ connecting the first end D₁ and ageometric center O₂ of the light-emitting element 30 and the thicknessdirection h1 of the backlight module 100 is greater than equal to 20°.Such a configuration can reduce the amount of small-angle light emittedfrom the light-emitting element 30 that is received by the convergingportion 122.

When the converging portion 122 includes a convex lens, in someembodiments of the present disclosure, the position and specification ofthe convex lens can be configured based on the specification of thelight-emitting element 30.

FIG. 13 is a sectional view of a light guide plate unit according toanother embodiment of the present disclosure. In some embodiments of thepresent disclosure, as shown in FIG. 13 , an angle (iii is formedbetween a connection line connecting the focus O₁ of the convex lens andthe center O₂ of the light-emitting element 30 and the thicknessdirection h1 of the backlight module 100. In some embodiments of thepresent disclosure, a critical light-exiting angle (not shown in FIG. 13) of light emitted from the light-emitting element that satisfies apreset light intensity condition is β₂. In some embodiments of thepresent disclosure, when configuring the convex lens, β₁₁=β₂.

Exemplarily, the preset light intensity condition can be configuredaccording to different optical performance requirements of the backlightmodule 100. For example, in some embodiments of the present disclosure,the preset light intensity condition can be defined as a light intensitygreater than or equal to half of the maximum light intensity. The lightintensity of the light-emitting element 30 is correlated to thelight-exiting angle of light emitted from the light-emitting element 30.Usually, the larger the light-exiting angle is, the smaller the lightintensity will be. When the light-exiting angle is equal to 0, that is,when the light-exiting direction is parallel to the normal line of thelight-exiting surface of the light-emitting element, the light intensityis the largest. When the preset light intensity condition is that thelight intensity is greater than or equal to half of the maximum lightintensity, the critical light-exiting angle β₂ herein indicates that thelight-emitting intensity is greater than or equal to half of the maximumlight-emitting intensity when the light-exiting angle is smaller than orequal to β₂.

In some embodiments of the present disclosure, β₁₁=β₂. On the one hand,the light within the critical light-exiting angle emitted from thelight-emitting element 30 after passing through the convex lens can exitfrom a side of the connection line O₁O₂ away from the reflection surface111 as far as possible, that is, the light within the criticallight-exiting angle emitted from the light-emitting element 30 can bedirected to the reflection surface 111 as little as possible, and exitfrom the light guide plate assembly 1 directly after passing through thetransmission portion 12 as much as possible, so as to reduce the lightloss caused by reflection of the reflection surface 111 and thus improvethe light intensity utilization rate. On the other hand, for the lightwith an angle greater than the critical light-exiting angle emitted fromthe light-emitting element, based on this configuration, this part oflight can be directed from a side of the connection line O₁O₂ adjacentto the reflection surface 111 towards the convex lens as far as possibleso as to be converged, which is conductive to increasing the lightintensity at the position adjacent to the edge S of the aperture H.

When the converging portion 122 includes a convex lens, in someembodiments of the present disclosure, as shown in FIG. 13 , theconnection line O₁O₂ connecting the focus O₁ of the convex lens and thecenter O₂ of the light-emitting element 30 intersects with the convexlens at a first intersection B. A tangent line of the convex lens at thefirst intersection B is perpendicular to the connection line O₁O₂connecting the focus O₁ of the convex lens and the center O₂ of thelight-emitting element 30. With such a configuration, on the one hand,the light emitted from the light-emitting element 30 and propagating ata side of the connection line O₁O₂ adjacent to the center of theaperture H can exit after passing through the transmission portion 12 asmuch as possible, and be directed to the reflection surface 111 aslittle as possible, so as to reduce the light loss caused by reflectionof the reflection surface 111 and thus improve the light intensityutilization rate. On the other hand, for the light with an angle greaterthan the critical light-exiting from emitted from the light-emittingelement 30, based on this configuration, this part of light can bedirected from a side of the connection line O₁O₂ adjacent to thereflection surface 111 towards the convex lens as far as possible so asto be converged, which is conductive to increasing the light intensityat the position adjacent to the edge S of the aperture H.

The curvature of the converging portion 122 adjacent to thelight-incoming side 101 of the light guide plate assembly 1 is 0, andalong a direction X1 from the edge of the aperture H to a center of theaperture H, a distance between the first surface P1 and thelight-exiting surface of the light guide plate assembly 1 decreasesgradually. In this case, as shown in FIG. 5 , an angle β₁₂ is formedbetween the first surface P1 and the thickness direction h1 of thebacklight module 100, and a critical light-exiting angle of the lightemitted from the light-emitting element 30 that satisfies a preset lightintensity condition is defined as β₂ (not shown). In some embodiments ofthe present disclosure, β₁₂+β₂=90°. That is, the first surface P1 isperpendicular to the propagation direction of the light with thecritical light-exiting angle. With such a configuration, on the onehand, the light within the critical light-exiting angle emitted from thelight-emitting element 30 can exit after passing through thetransmission portion 12 as much as possible, and be directed to thereflection surface 111 as little as possible, so as to reduce the lightloss caused by reflection of the reflection surface 111 and thus improvethe light intensity utilization rate. On the other hand, for the lightwith an angle greater than the critical light-exiting angle emitted fromthe light-emitting element 30, based on this configuration, this part oflight can be converged by the converging portion 122 as much aspossible, which is conductive to increasing the light intensity at theposition adjacent to the edge S of the aperture H.

Exemplarily, referring to FIG. 10 and FIG. 11 , a surface of thetransmission portion 12 adjacent to a light-exiting side 102 of thelight guide plate assembly 1 includes a third microstructure 23, andalong a direction parallel to a plane of the light guide plate assembly1, a distance between the third microstructure 23 and the center of theaperture H is defined as L. The distance L between the thirdmicrostructure 23 and the center of the aperture H refers to theshortest distance between the third microstructure 23 and the center ofthe aperture H. In some embodiments of the present disclosure, L>0.

Exemplarily, a critical light-exiting angle of the light emitted fromthe light-emitting element 30 that satisfies a preset light intensitycondition is defined as β₂, a refractive index of the transmissionportion 12 is defined as n₁, a refractive index of a medium at a side ofthe light guide plate assembly 1 away from the light-emitting element 30is defined as n₂, a refractive index of a medium between thelight-emitting element 30 and the transmission portion 12 is defined asn₃, a distance between a geometric center of the light-emitting element30 and a light-exiting surface of the light guide plate assembly 1 isdefined as H; then, in some embodiments of the present disclosure,L≥H×tan θ₁, and

$\theta_{1} = {\beta_{2} - {{\arcsin\left\lbrack {\frac{n_{1}}{n_{2}}{\sin\left( {\beta_{2} - {\arcsin\frac{n_{3}}{n_{1}}}} \right)}} \right\rbrack}.}}$

FIG. 14 is a schematic diagram of a position disposing principle of athird microstructure of a light guide plate unit according to anembodiment of the present disclosure. Referring to FIG. 14 , for thecritical light Rc emitted from the light-emitting element 30, where thecritical light Rc refers to light emitted from the light-emittingelement 30 that can have a total reflection when being directed to thelight-exiting surface of the light guide plate assembly 1. As shown inFIG. 14 , an angle θ₁ is formed between the propagation direction of thecritical light Rc and the thickness direction of the light guide plateassembly 1. In some embodiments of the present disclosure, L≥H×tan θ₁,it can ensure that the third microstructure (not shown in FIG. 14 ) cancover the distribution range of the light-exiting surface of the lightthat would have total reflection on the light guide plate assembly 1, sothat the third microstructure can reduce the incident angle of this partof light when being directed to the light-exiting surface of the lightguide plate assembly 1, and this part of light can exit from the guidelight guide plate assembly 1.

As shown in FIG. 14 , θ₁=θ₂−θ₃, where, θ₂ is an angle formed between anormal line of a surface of the transmission portion 12 adjacent to thelight-emitting element 30 and the thickness direction h1 of the lightguide plate assembly 1; and θ₃ is an angle formed between a normal lineof a surface of the transmission portion 12 adjacent to thelight-emitting element 30 and the critical light Rc.

Moreover, n₃ sin θ₃=n₁ sin θ₄ (where θ₄ is an angle formed between thelight corresponding to the critical light Rc that emits from the surfaceof the transmission portion 12 adjacent to the light-emitting element 30and the thickness direction h1 of the light guide plate assembly 1) andθ₆=θ₄+θ₅ (where θ₅ is an angle formed between the propagation directionof the critical light Rc when being directed to the light-exitingsurface of the light guide plate assembly 1 and the thickness directionh1 of the light guide plate assembly 1). Since the critical light Rc hasa full reflection when exiting from the light guide plate assembly 1,

${\theta_{5} = {\arcsin\frac{n_{3}}{n_{1}}}};$θ₆ is an angle formed between a normal line of part of the surface ofthe transmission portion 12 adjacent to the light-emitting element 30and the thickness direction h1 of the light guide plate assembly 1.

For example, when part of the surface of the transmission portion 12adjacent to the light-emitting element 30 is perpendicular to thepropagation direction of the light emitted from the light-emittingelement 30 with the above critical light-exiting angle β₂, θ₆=θ₂=β₂. Itcan be derived from the above that: θ=β₂

$- {{\arcsin\left\lbrack {\frac{n_{1}}{n_{2}}{\sin\left( {\beta_{2} - {\arcsin\frac{n_{3}}{n_{1}}}} \right)}} \right\rbrack}.}$

Exemplarily, the medium located at a side of the light guide plateassembly away from the light-emitting elements 30, and the mediumbetween the light-emitting element 30 and the transmission portion 12can be air, that is, n₂=1, and n₃=1.

It should be noted that FIG. 14 merely schematically illustrates theposition of the third microstructure by taking the curvature of part ofthe surface of the transmission portion 12 adjacent to thelight-emitting element 30 being 0 as an example. When the curvature ofpart of the surface of the transmission portion 12 adjacent to thelight-emitting element 30 is greater than or smaller than 0, as shown inFIG. 10 , the position configuration of the third microstructure 23 isalso applicable.

In some embodiments of the present disclosure, as shown in FIG. 10 andFIG. 11 , the third microstructure 23 includes saw teeth, each one ofwhich includes an oblique surface 230, an angle α₂ formed between theoblique surface 230 and the thickness direction h1 of the light guideplate assembly 1 satisfies α₂=90°−θ₁. With such a configuration, it isequivalent to that, the propagation direction of the critical light withtotal reflection emitted from the light-emitting element 30 is parallelto a normal direction of the oblique surface 230, thereby increasing thebrightness of light perpendicularly emitted from the light-exitingsurface of the light guide plate assembly 1.

In some embodiments of the present disclosure, as shown in FIG. 10 andFIG. 11 , the saw tooth can include one oblique surface 230. That is, across-sectional shape of the saw tooth is a right triangle as shown inFIG. 10 and FIG. 11 , and the oblique surface 230 corresponds to thehypotenuse of the right triangle.

FIG. 15 is a sectional view of a light guide plate unit according toanother embodiment of the present disclosure. In some embodiments of thepresent disclosure, as shown in FIG. 15 , the saw tooth includes twooblique surfaces 230. That is, the cross-sectional shape of the sawtooth is an isosceles triangle as shown in FIG. 15 , and the two obliquesurfaces 230 correspond to two waists of the isosceles triangle.

The present disclosure further provides a display device. FIG. 16 is aschematic diagram of a display device according to an embodiment of thepresent disclosure. As shown in FIG. 16 , the display device includes adisplay panel and the backlight module 100 described above. The displaypanel is located at a light-exiting side of the backlight module 100.The display panel includes a LCD display panel. A structure of thebacklight module 100 has been described in detail in the foregoingembodiments, and will not be repeated herein. The display device shownin FIG. 16 is merely a schematic illustration, which can be anyelectronic device with a display function, such as a mobile phone, atablet computer, a laptop computer, an e-paper book, or a television.

The above are merely some embodiments of the present disclosure, which,as mentioned above, are not configured to limit the present disclosure.Whatever within the principles of the present disclosure, including anymodification, equivalent substitution, improvement, etc., shall fallinto the protection scope of the present disclosure.

What is claimed is:
 1. A light guide plate assembly, comprising: areflection portion having an aperture; and a transmission portion,wherein at least part of the transmission portion is located in theaperture; the transmission portion comprises a converging portion and adiverging portion; the converging portion is configured to make lightthat enters the converging portion be converged towards a direction awayfrom a center of the aperture, the diverging portion is configured tomake light that enters the diverging portion be diverged towards thedirection away from the center of the aperture; and the convergingportion is located at a side of the transmission portion away from thecenter of the aperture.
 2. The light guide plate assembly according toclaim 1, wherein the reflection portion comprises a reflection surfaceand a bottom surface that is located at a side adjacent to alight-incoming side of the light guide plate assembly, and an angle α1is formed between the reflection surface and the bottom surface, where0°<α1<90°.
 3. The light guide plate assembly according to claim 1,wherein a surface of the diverging portion adjacent to a light-incomingside of the light guide plate assembly comprises a secondmicrostructure.
 4. The light guide plate assembly according to claim 1,wherein the converging portion comprises a convex lens located at a sideof the transmission portion adjacent to a light-incoming side of thelight guide plate assembly.
 5. The light guide plate assembly accordingto claim 4, wherein the reflection portion comprises a reflectionsurface that surrounds the aperture, and the reflection surfacecomprises a first edge adjacent to a light-exiting side of the lightguide plate assembly; and wherein a focus of the convex lens is locatedon the first edge or at a side of the reflection surface adjacent to thelight-exiting side of the light guide plate assembly.
 6. The light guideplate assembly according to claim 1, wherein a surface of the convergingportion adjacent to a light-incoming side of the light guide plateassembly comprises a first surface with a curvature of 0, and a distancebetween the first surface and a light-exiting surface of the light guideplate assembly decreases along a direction from an edge of the apertureto the center of the aperture.
 7. The light guide plate assemblyaccording to the claim 6, wherein a surface of the diverging portionadjacent to the light-incoming side of the light guide plate assemblycomprises a second surface with the curvature of 0, and a distancebetween the second surface and the light-exiting surface of the lightguide plate assembly decreases along the direction from the edge of theaperture to the center of the aperture.
 8. The light guide plateassembly according to the claim 6, wherein the diverging portioncomprises a third surface adjacent to the light-incoming side of thelight guide plate assembly, and a distance between the third surface andthe light-exiting surface of the light guide plate assembly firstdecreases and then increases along the direction from the edge of theaperture to the center of the aperture.
 9. The light guide plateassembly according to the claim 8, wherein the third surface comprises afirst sub-surface adjacent to the first surface, and the firstsub-surface and the first surface have a same curvature.
 10. The lightguide plate assembly according to claim 1, wherein the diverging portioncomprises a concave lens located at a side of the transmission portionadjacent to a light-incoming side of the light guide plate assembly. 11.The light guide plate assembly according to claim 1, wherein thediverging portion corresponds to the center of the aperture.
 12. Thelight guide plate assembly according to claim 1, wherein a surface ofthe transmission portion adjacent to a light-exiting side of the lightguide plate assembly comprises a third microstructure, and a distancebetween the third microstructure and the center of the aperture isgreater than 0 in a direction parallel to a plane of the light guideplate assembly.
 13. A backlight module, comprising a light-emittingelement and the light guide plate assembly according to claim 1, thelight guide plate assembly being located at a light-exiting side of thelight-emitting element.
 14. The backlight module according to the claim13, wherein the light-emitting element is located at side of thetransmission portion adjacent to a light-incoming side of the lightguide plate assembly, and at least part of the light-emitting element islocated in the aperture.
 15. The backlight module according to the claim13, wherein along a thickness direction of the backlight module, thelight-emitting element at least partially overlaps with the divergingportion.
 16. The backlight module according to the claim 13, whereinalong a thickness direction of the backlight module, the light-emittingelement does not overlap with the converging portion.
 17. The backlightmodule according to the claim 13, wherein the converging portioncomprises a convex lens located at a side of the transmission portionadjacent to a light-incoming side of the light guide plate assembly; andwherein an angle formed between a connection line connecting a focus ofthe convex lens and a center of the light-emitting element and athickness direction of the backlight module is defined as β₁₁, and acritical light-exiting angle of light emitted from the light-emittingelement that satisfies a preset light intensity condition is defined asβ₂, where β₁₁=β₂.
 18. The backlight module according to the claim 13,wherein the converging portion comprises a convex lens located at a sideof the transmission portion adjacent to a light-incoming side of thelight guide plate assembly; and wherein a connection line connecting afocus of the convex lens and a center of the light-emitting elementintersects with the convex lens at a first intersection point, and atangent line of the convex lens at the first intersection point isperpendicular to the connection line connecting the focus of the convexlens and the center of the light-emitting element.
 19. The backlightmodule according to the claim 15, wherein a surface of the convergingportion adjacent to a light-incoming side of the light guide plateassembly comprises a first surface; wherein a distance between the firstsurface and a light-exiting surface of the light guide plate assemblydecreases along a direction from an edge of the aperture to the centerof the aperture; and wherein an angle formed between the first surfaceand the thickness direction of the backlight module is defined as β₁₂,and a critical light-exiting angle of light emitted from thelight-emitting element that satisfies a preset light intensity conditionis defined as β₂, where β₁₂+β₂=90°.
 20. A display device, comprising adisplay panel and the backlight module according to claim 13, whereinthe display panel is located at a light-exiting side of the backlightmodule.